delete manager added

5 files changed, 49 insertions, 0 deletions

diff --git a/lib/arel/crud.rb b/lib/arel/crud.rb
index 7f78acef84..6861ff016c 100644
--- a/lib/arel/crud.rb
+++ b/lib/arel/crud.rb
@@ -22,5 +22,12 @@ module Arel
       im.insert values
       @engine.connection.execute im.to_sql
     end
+
+    def delete
+      dm = DeleteManager.new @engine
+      dm.wheres = @ctx.wheres
+      dm.from @ctx.froms.last
+      @engine.connection.execute dm.to_sql
+    end
   end
 end
diff --git a/lib/arel/delete_manager.rb b/lib/arel/delete_manager.rb
new file mode 100644
index 0000000000..4759f116f1
--- /dev/null
+++ b/lib/arel/delete_manager.rb
@@ -0,0 +1,22 @@
+module Arel
+  class DeleteManager < Arel::TreeManager
+    def initialize engine
+      super
+      @head = Nodes::DeleteStatement.new
+    end
+
+    def from relation
+      @head.relation = relation
+      self
+    end
+
+    def where expression
+      @head.wheres << expression
+      self
+    end
+
+    def wheres= list
+      @head.wheres = list
+    end
+  end
+end
diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb
index bf144ecaf8..4d6db39aec 100644
--- a/lib/arel/nodes.rb
+++ b/lib/arel/nodes.rb
@@ -8,4 +8,5 @@ require 'arel/nodes/select_core'
 require 'arel/nodes/select_statement'
 require 'arel/nodes/insert_statement'
 require 'arel/nodes/update_statement'
+require 'arel/nodes/delete_statement'
 require 'arel/nodes/unqualified_column'
diff --git a/lib/arel/nodes/delete_statement.rb b/lib/arel/nodes/delete_statement.rb
new file mode 100644
index 0000000000..54bf513c2b
--- /dev/null
+++ b/lib/arel/nodes/delete_statement.rb
@@ -0,0 +1,12 @@
+module Arel
+  module Nodes
+    class DeleteStatement
+      attr_accessor :relation, :wheres
+
+      def initialize
+        @from   = nil
+        @wheres = []
+      end
+    end
+  end
+end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index fd467495ae..0e5998c573 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -12,6 +12,13 @@ module Arel
       end
 
       private
+      def visit_Arel_Nodes_DeleteStatement o
+        [
+          "DELETE FROM #{visit o.relation}",
+          ("WHERE #{o.wheres.map { |x| visit x }.join ' AND '}" unless o.wheres.empty?)
+        ].compact.join ' '
+      end
+
       def visit_Arel_Nodes_UpdateStatement o
         [
           "UPDATE #{visit o.relation}",